Spatial and temporal variations in carbon and sulfur isotopic compositions of Sinian sedimentary rocks in the Yangtze platform, South China

Abstract. Research on Lower Cambrian siliceous sedimentary rocks is important for understanding the origin and early involvement of polycystine Radiolaria in the silica cycle. During our study, thin sections and HF acid processing of black cherts and shales from the Hetang Formation that crops out in the Xintangwu section (west Zhejiang Province, south China) were made. We report on the presence of siliceous spherical microfossils (possibly Radiolaria) associated with sponge spicules and acritarchs. Their size and the presence of residual spines on some spherical siliceous microfossils observed in both residues and thin sections of cherts from the top of Member ‘a’ of the Hetang Formation argue for the possible presence of radiolarians. Based on the Small Shelly Fossil assemblages reported in previous studies, this interval should be considered as Qiongzhusian (Atdabanian–Early Botomian) in age. Finally, the values of the Ge/Si ratio measured on black cherts of the Hetang Formation point to a biogenic origin of the silica.

Download Full-text

Spatial and temporal variations in algal blooms in the coastal waters of the western South China Sea

Journal of Hydro-environment Research ◽

10.1016/j.jher.2012.02.002 ◽

2012 ◽

Vol 6 (3) ◽

pp. 239-247 ◽

Cited By ~ 8

Author(s):

ChunLi Liu ◽

DanLing Tang

Keyword(s):

South China Sea ◽

South China ◽

Coastal Waters ◽

Algal Blooms ◽

Temporal Variations ◽

Spatial And Temporal Variations ◽

China Sea ◽

Western South China Sea

Download Full-text

Spatial variation of carbon isotopic compositions of carbonate and organic matter from the Late Ordovician sedimentary succession in the Yangtze Platform, South China: Implications for sea – Level eustacy and shoaling of marine chemocline

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2020.104540 ◽

2020 ◽

Vol 202 ◽

pp. 104540

Author(s):

Xiangrong Yang ◽

Detian Yan ◽

Daizhao Chen ◽

Mu Liu ◽

Xiaohui She ◽

...

Keyword(s):

Organic Matter ◽

Spatial Variation ◽

Sea Level ◽

South China ◽

Late Ordovician ◽

Yangtze Platform ◽

Isotopic Compositions ◽

Carbon Isotopic ◽

Sedimentary Succession

Download Full-text

Late Tremadocian (Early Ordovician) reefs on the Yangtze Platform, South China, and their geobiological implications: a synthesis

Journal of Palaeogeography ◽

10.1186/s42501-021-00086-0 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Jian-Po Wang ◽

Qi-Jian Li ◽

Stephen Kershaw ◽

Yuan-Yuan Zhang ◽

Shen-Yang Yu ◽

...

Keyword(s):

South China ◽

High Salinity ◽

Sedimentary Rocks ◽

Nutrient Supply ◽

Low Oxygen ◽

Yangtze Platform ◽

Intertidal Zones ◽

Early Ordovician ◽

Low Latitudes ◽

Near Shore

AbstractThis study provides an overview and discussion of controls on the distribution of organic reefs during the Early Ordovican Period, in the Yangtze Platform, a region of epicontinental sedimentary rocks in South China. The Yangtze Platform was located in low latitudes during the Early Ordovician and recorded rich and diverse reefs through that time. During the late Tremadocian Epoch, dolomitic and stratiform stromatolites were common in supratidal to intertidal zones of the western Yangtze Platform, while columnar stromatolites formed in deeper waters of the eastern Yangtze Platform. Skeletal-dominated reefs occurred in upper subtidal settings of the central Yangtze Platform. A transition from microbial-dominated to metazoan-dominated reefs with shallowing-upward cycles was evident, indicating that the composition of the main reef-builders was driven mainly by water depth. Increasing metazoan competition during the Great Ordovician Biodiversification Event reduced the abundance of microbial reefs. Sufficient nutrient supply is interpreted to have promoted development of skeletal-dominated reefs locally in shallow settings in the central Yangtze Platform, especially represented by the expansion of abundant solitary fossils of lithistid sponges and Calathium. High salinity environmental settings facilitated the bloom of stromatolites in near-shore locations. Low oxygen content in deep subtidal settings may have led to the absence of skeletal reefs in these habitats, so the mass occurrences of stromatolites was located in the shallower-water central and eastern platform. No keratose sponge-bearing stromatolite can be confirmed across the platform during this interval.

Download Full-text